1. Field of the Invention
The present invention generally pertains to an electrical connector housing to be mounted in a vehicle, e.g. an automobile (car). In particular, the invention relates to an electrical connector housing including separate busbar modules for connecting connectors, fuses and relays, so that the materials of busbars for each module can be chosen appropriately.
2. Description of Background Information
Electrical devices for vehicles, such as relays, fuses and connectors, are generally held in an electrical connector housing, which is in turn mounted inside a vehicle. Such an electrical connector housing contains various kinds of electrical devices connected through connector circuits, which are commonly composed of busbars.
FIG. 1 shows a known electrical connector housing 51 including a first shell 52 and a second shell 53 fit thereto. The first shell 52 is fit with connector mounts (not shown in the figures), relay mounts 54 and fuse mounts 55. The connector mounts hold corresponding connectors (not shown in the figures). Likewise, the fuse mounts 55 hold corresponding fuses (not shown in the figures) by means of intermediate terminals 62a, while the relay mounts 54 hold corresponding relays (not shown in the figures) by means of intermediate terminals 62b. 
The electrical connector housing 51 contains a busbar stack 56 formed by alternating layers of a group of busbars 60 made of pure copper, and an insulator sheet 61. The busbar stack 56 includes a connector circuitry module 57, a fuse circuitry module 58 and a relay circuitry module 59. The connector circuitry module 57 is connected to the connector mounts, and is connected to the connectors to be fit therein. Likewise, a fuse circuitry module 58 is connected to the fuse mounts 55, and connected to the fuses to be fit therein, whilst the relay circuitry module 59 is connected to the relay mounts 54, and is connected to the relays to be fit therein.
However, the busbars 60 consisting of pure copper are very soft, and cannot be connected directly to the fuses and relays. For these reasons, the intermediate terminals 62a and 62b are provided at positions between the busbars 60 and the fuse and relay terminals. As a result, in the prior art electrical connector housings 51, the number of electrical components tends to increase, and the housing structure is rather complex.
To circumvent such problems, attempts have been made to replace the pure copper of busbars with a harder copper alloy, and to obviate the intermediate terminals 62a and 62b. However, the busbars 60 connected to the connectors, the fuses and the relays are usually contained in an electrical connector housing in a mixed form, so that the pure copper material of all the busbars 60 must be replaced by a copper alloy. The costs necessary for the replacement then often exceed those for installing the intermediate relays 62a and 62b, and increase the housing""s construction costs.
The present invention has been conceived to solve such problems, and provides an electrical connector housing that has a simpler structure and can be manufactured with lesser costs.
To this end, the present invention provides an electrical connector housing including a first shell and a second shell mounted on it. The first shell is provided with connector mounts to be fit with connectors, fuse mounts to be fit with fuses and relay mounts to be fit with relays. The electrical connector housing also contains a busbar stack which includes a connector circuitry module containing connector-connecting circuits connected to the connector mounts, a fuse circuitry module containing fuse-connecting circuits connected to the fuse mounts, and a relay circuitry module containing relay-connecting circuits connected to the relay mounts.
In the present invention, the fuse-connecting circuits contain first busbars with first tabs, while the relay-connecting circuits contain second busbars with second tabs.
Furthermore, at least one of the first busbars and the second busbars is formed of a resilient conductor harder than pure copper.
The first tabs and the second tabs are then directly connected to the fuses and the relays, respectively.
The resilient conductor that is harder than pure copper is preferably a copper alloy.
Alternatively, the resilient conductor that is harder than pure copper is iron.
The fuse circuitry module is formed in a suitable manner integrally with the relay circuitry module, and the first busbars are formed unitarily and in one piece with the second busbars.
Typically, the first tabs and the second tabs are provided with notches configured to hold the fuses and the relays respectively.
In a first embodiment of the present invention, the busbars forming at least one of the fuse-connecting circuits and relay-connecting circuits are formed of a copper alloy which is harder than pure copper, so that intermediate terminals commonly installed between the tab sections of busbar and the fuses and relays can be obviated. Furthermore, the connector-connecting circuits, the fuse-connecting circuits and the relay-connecting circuits are formed into separate modules. In this manner, only the busbars that form the fuse-connecting circuits and relay-connecting circuits can be composed of a copper alloy. As a result, the replacement costs are kept lower than the costs for providing the intermediate terminals. The electrical connector housing thus produced has a simpler structure and incurs lower costs.
In a second embodiment of the present invention, the busbars forming the fuse-connecting circuits and those forming the relay-connecting circuits are formed integrally, so that areas for busbar connections are reduced in size. This in turn makes it easier to manufacture the electrical connector housing, and miniaturize its structure.
In a third embodiment of the present invention, the end sections of fuses and relays are held by notched sections in the busbar terminals, so that the fuses and the relays are more securely connected to the busbar terminals (tab sections of busbars).